APPENDIX III
ARCHONTIC (CIVIL) YEAR
INTERCALATIONS
The Placement of Embolismic Months
Chapter from the forthcoming Athenian Year Primer Vol. II. The
excerpt presupposes familiarity with the methodologies and
arguments presented in AYP.
Chapter tackles one of the most fundamental and crucial yet
least understood calendrical practices, which all lunisolar
calendars must follow: insertion of an extra (thirteenth) lunar
month to keep a lunar year’s Synodic Cycles aligned to a Sidereal
Solar Year (i.e., solstice ↔ solstice or equinox ↔ equinox).
1) Show that ancient Greeks across the ancient Aegean proved far
more astronomically savvy than currently appreciated.
2) Argue that ancient Athenians could not have used any fixed or
absolute thus, in effect, arbitrarily inserted embolismic month to
keep Archontic Years aligned. Significant, existential (practical)
considerations existed.
3) Consequently, also argue that intercalations must have
possessed “rules” or at least firmly established “guidelines.” The
most obvious in fact being any number of seasonal festivals (e.g.,
Anthesteria, Eleusinian Mysteries). Seasonal festivals, moreover,
promptly follow all Panhellenic gatherings (addressed in
subsequent Chapters).
4) Attempt to unlock the methodologies used so one can not only
understand the underlying math but also establish the base
astronomical “template.”
5) Finally, knowing what Calendar Equations ought have occurred
aids greatly when working with recovered epigraphical evidence
that display such equations. When any deviations surface, we
can develop a thorough understanding of why they took place.
Copyright © 2023 by Christopher Planeaux. Published in the United States of
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ISBN: [Pending]
CHAPTER XX
J
CIVIL CALENDAR INTERCALATION
Note: this chapter supersedes AYP 159-160 and expands
considerably upon the brief Intercalation schemas given pp.
177-180 and therefore also affects Appxs. IV-VI & X-XI.
A functional lunisolar calendar requires constant and
continuous observations of but two celestial objects: the Moon
against the Sun. Ancient Athenian astronomers reckoned four
key solar events against four of twelve (or thirteen) lunar events
throughout a given “year.” This patent obviousness masks a
underlying complexity: their combined movements will at times
prove frustratingly ambiguous.
Let us assume all ancient Greek povlei~ attempted, however
imperfectly, to keep Civil Months aligned with the Moon and then
Civil Years aligned to the Seasons. Calendrical deviations from
the sky should not a priori indicate indifference or evidence the
basileuv~ (or ejkklhsiva) wantonly inserted or omitted days (or whole
months) but also entertain that some may have reflected
observational uncertainties, which required human decisions.
The Moon appears illumed possessing the same phase from
every location on Earth, i.e., within the same hemisphere each
side of the equatorial line (AYP 116-117). The most important
astronomical quality to know for the arrival of a 1stVisCres
becomes the Moon’s elongation (AYP 116, 239-243). The math
remained unknown to ancient Greeks, but the varying sizes and
elevations the initial, readily visible crescents possessed month to
month could not have eluded even casual observations.
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
Under optimal viewing conditions, the lunar crescent will first
become observable on the same day (sans topographical
obstructions) from Makedonia to Babylon to Egypt to Syracuse to
Korkyra (and of course everywhere in between). In other words,
ancient Athenians, Spartans, Thebans, Epidaurians, Eleans,
Nemeans, Delians, Corinthians et al. would all gaze upon the
same Moon on the same night every synodic cycle. 13
Consequently, the counts of synodic cycles between solar or
stellar events, e.g., VerEqu to AS a CMa (Seirios) remained the
same every year for all ancient Greek povlei~ regardless what time
of year their Civil Years began (relative to each other). This
astronomical certainty permitted fiercely independent ancient
Greek povlei~, who zealously protected their aujtonomiva, ejleuqeriva,
and aujtokravteia, to develop and maintain local, internally
functional yet quite different lunisolar calendars that also
progressed coterminous or at least parallel with each other.
Despite the (apparently still) prevailing communis opinio that
ancient Greek calendars developed and stood horrifically chaotic
and haphazardly diverged from one another, the premise
ultimately proves untenable. The posit collapses for one reason
above all others: annual, biennial, quadrennial, quintennial et al.
Panhellenic Festivals. Participants, in short, needed to know
when to gather again at quite distant locales well in advance.
The Basics
The math, which determines when extra ancient Attic Civil
Months needs inserted, proves surprisingly straightforward. If the
current Civil Year’s 1stVisCres appeared < 21 days after SumSol,
then the next Civil Year becomes embolismic. More precisely, the
thirteenth synodic cycle after each SumSol runs (read L → R):
Days SumSol to 1stVisCres
Current Civil Year
Next Civil Year
Following Civil Year
10 ↔ 12
0↔1
-11 ↔ -10
13 ↔ 15
2↔4
-9 ↔ -7
16 ↔ 17
5↔6
-6 ↔ -5
18 ↔ 21
7 ↔ 10
-4 ↔ -2
During all Ordinary Attic Civil Years, moreover, four specific
Civil Months naturally and always aligned to four specific Solar
Events: Boid = AutEqu; Pos = WinSol; Elaph = VerEqu; and Skir =
SumSol. The premise: embolismic years sought to preserve these
alignments. Nothing more complicated than math proves
necessary but comes with a question: whether a solstice or
equinox ought always fall during the nominal Civil Month or
could have fallen during its embolismic partner.
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
When composing the Primer, I did not give this question much
thought. Regardless, as with everything regarding ancient Attic
time-reckoning, “best practices” cannot become “inflexible rules.”
Undoubtedly different basilei`~ facing different circumstances
could choose (or recommend to the ejkklhsiva) different courses of
actions down through the centuries. We shall return to this
specific question end of chapter.
For now, if an anchor solar event ought fall during the nominal
Civil Month, then intercalations progress inside small count-ofday windows. When reckoning solstices and equinoxes by a Boö
(AYP 157-160), the numbers of days between events ran (note:
Julian-Gregorian Leap Year = 4):
→
→
→
→
SumSol
AutEqu
WinSol
VerEqu
AutEqu
WinSol
VerEqu
SumSol
=
=
=
=
Yr 1
Yr 2
Yr 3
Yr 4
92
87
91
95
365
92
88
90 (91)
95 (94)
365
92
88
91
95
366
91
88
91
95
365 a
Ancient Athenian astronomers then ran six systematic Civil
Month scenarios to establish “baseline” noumhnivai for Civil Months
IV, VII, X, and (the following) I: 1) FHFHFHFHFHFH & 2) HFHFHF
HFHFHF; 3) FFHHFFHHFFHH & 4) HHFFHHFFHHFF; then 5) FF
FHHHFFFHHH; and 6) HHHFFFHHHFFF.
Scenario
1:
2:
3:
4:
5:
6:
Days
Days
Days
Days
Days
Days
=
=
=
=
=
=
1 Pyan
1 Gam
1 Moun
1 Hek
90
89
90
89
91
88
178
178
179
177
178
178
267
266
267
266
268
265
355
355
355
355
355
355
(89)
(90)
(90)
(89)
(88)
(91)
(90)
(89)
(89)
(90)
(91)
(88)
(89)
(90)
(90)
(90)
(88)
(91)
These six scenarios represent ideal count averages (essentially)
from one extreme to the other. Pyan noumhniva could fall Day 8891; Gam noumhniva Day 177-179; Moun noumhniva Day 265-268;
with Hek noumhniva always on Day 355. During the years covered
by the Primer, however, a seventh plhvrh~ month occurred sixteen
times: 460/59, 452/1, 451/0, 443/2, 441/0, 434/3, 432/1,
429/8, 424/3, 418/7, 415/4, 408/7, 405/4, 400/399, 399/8,
and 396/5 BCE. These introduced ±1 solar day by end-of-year.
a) Prior to Meton & Euktemon (463 – 432 BCE), ancient Athenians ought have reckoned
SumSol 29, 29, 29, 30 Jun; AutEqu 29, 29, 29, 28 Sep; WinSol 25, 26, 26, 26 Dec; and
VerEqu 26, 26, 27, 26 Mar; after 432 BCE , SumSol 28, 28 , 28, 29 Jun; AutEqu 28, 28, 28, 29
Sep; WinSol 24, 25, 25, 25 Dec; and VerEqu 25, 25, 26, 25 Mar. As a consequence, Yr 2
shifted to 92 88 91 94 (Chap. XX, pp. xxx-xxx).
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
The next required variable becomes the number of days after
SumSol the initial 1stVisCres actually appeared. Working large to
small for illustration purposes, deviations run:
461/0 BCE:
SumSol =
Day 1
29 Jun
AutEqu
=
Day 92
→
→
1 Hek
=
1 Pyan
=
28 Sep
WinSol
=
Day 180 →
=
Day 271 →
SumSol =
Day 366 →
Days 96 – 99
2 – 5 Oct
1 Gam
=
Days 185 – 187
1 Moun
=
Days 273 – 276
1 Hek
=
Day 362
25 Dec
VerEqu
Day 8
7 Jul
31 Dec – 2 Jan
26 Mar
28 – 31 Mar
29 Jun
26 Jun
Next 1 Hek arrives four days before SumSol, but AutEqu
would still fall in Boid, WinSol in Pos, and VerEqu in Elaph. The
basileuv~ (or ejkklhsiva) could have inserted an embolismic Moun,
Thar, or Skir without any (apparent) seasonal disruption.
439/8 BCE:
SumSol =
Day 1
29 Jun
AutEqu
=
Day 93
→
→
1 Hek
=
1 Pyan
=
29 Sep
WinSol
=
Day 181 →
=
Day 272 →
1 Gam
=
1 Moun
=
Day 367 →
Days 183 – 185
28 – 30 Dec
27 Mar
SumSol =
Days 94 – 97
30 Sep – 3 Oct
26 Dec
VerEqu
Day 6
5 Jul
Days 271 – 274
26 – 29 Mar
1 Hek
=
30 Jun
Day 361
24 Jun
Next 1 Hek arrives five days before SumSol. AutEqu still falls
in Boid and WinSol in Pos. VerEqu, on the other hand, possessed
a 50% chance of falling in Moun. The basileuv~ (or ejkklhsiva) could
have therefore inserted an embolismic Pos, Gam, Anth, or even
Elaph. A seasonal disruption, however, might take place.
409/8 BCE:
SumSol =
Day 1
28 Jun
AutEqu
=
Day 92
→
→
1 Hek
=
1 Pyan
=
28 Sep
WinSol
=
Day 179 →
=
Day 271 →
1 Gam
=
Day 366 →
28 Jun
Days 181 – 183
25 – 27 Dec
1 Moun
=
26 Mar
SumSol =
Days 92 – 95
27 - 30 Sep
24 Dec
VerEqu
Day 4
2 Jul
Days 269 – 272
23 – 26 Mar
1 Hek
=
Day 359
22 Jun
This alignment proves trickier. Next 1 Hek arrives six days
before SumSol. AutEqu, however, had but a 75% chance of falling
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
in Boid. WinSol falls squarely in Pos, but VerEqu then possessed
a 50% chance of falling in Moun. The basileuv~ (or ejkklhsiva) could
have inserted an embolismic Pos, Gam, Anth, or even Elaph once
again, but more than one seasonal disruption might appear.
436/5 BCE:
SumSol =
Day 1
29 Jun
AutEqu
=
Day 93
→
→
1 Hek
=
1 Pyan
=
29 Sep
WinSol
=
Day 181 →
=
Day 271 →
1 Gam
=
1 Moun
=
Day 366 →
Days 179 – 181
24 – 26 Dec
27 Mar
SumSol =
Days 90 – 93
26 Sep – 29 Oct
26 Dec
VerEqu
Day 2
1 Jul
Days 267 – 270
22 – 5 Mar
1 Hek
=
29 Jun
Day 357
20 Jun
Every Civil Year with this count represents the most difficult to
keep aligned. Next 1 Hek arrives nine days before SumSol.
Moreover, both AutEqu & WinSol could but would not necessarily
fall outside Boid & Pos. VerEqu, on the other hand, still falls in
Moun. The basileuv~ (or ejkklhsiva) could have inserted an
embolismic month anytime Hek ↔ Anth (in theory), but at least
one seasonal disruption would almost certainly appear.
414/3 BCE:
SumSol =
Day 1
29 Jun
AutEqu
=
→
1 Hek
=
→
1 Pyan
=
Day 180 →
1 Gam
=
Day 92
28 Sep
WinSol
=
=
Day 271 →
Day 366 →
28 Jun
Days 177 – 179
22 – 24 Dec
1 Moun
=
25 Mar
SumSol =
Days 88 – 91
24 -27 Sep
25 Dec
VerEqu
Day 1
29 Jun
Days 265 – 268
19 – 22 Mar
1 Hek
=
Day 355
17 Jun
All Civil Years, which sported this count, represent the most
straightforward to have kept aligned throughout an entire Civil
Year. Next 1 Hek arrives eleven days before SumSol. More
significantly, all three remaining solar events (AutEqu, WinSol,
and VerEqu) fall outside their Ordinary Year Civil Months. The
basileuv~ (or ejkklhsiva) could therefore have inserted an
embolismic Hek, Met, or Boid.
The schemas suggest that, during the seventy years 462/1 ↔
393/2 BCE of the Primer, the basileuv~ (or ejkklhsiva) should have
inserted an embolismic Skir nine times, an embolismic Hek six
times, an embolismic Elaph five times, and then an embolismic
Boid & Pos three times each. If basilei`~ elected merely “to play
the odds,” then the baseline months for each range become:
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
SumSol to 1stVisCres
Number of Days
Embolismic Month
0↔1
II Hek
2↔3
II Boid
4
II Pos
5↔6
II Elaph
7 ↔ 10
II Skir
Math challenges a stubborn assumption that has guided
Ancient Athenian Calendrical Theory: the basileuv~ (or ejkklhsiva)
“regularly” intercalated a 2nd Pos during embolismic years (AYP
160, cf. 368n43). Most deviations during twelve month rolling
synodic cycles in fact manifest during Summer. Some begin to
appear by Spring, and early-Sum fell during a different Archontic
Year than late-Sum. The only attested intercalation that survives
from the 5th Century, moreover, indeed inserts II Hek, or lateSummer, not II Pos or mid-Winter (IG I3 73; AYP 382 n. 126).
Regardless this exercise represents the (small) first step.
Ancient Athenians, for instance, held four grand Panhellenic
festivals: Great Panathenaia, Eleusinian Mysteries, Mysteries of
Agrai, and City Dionysia. These of course rigorously followed the
ancient Attic Civil Calendar, but, to prove manageable thus
successful, these four also demanded consistent schedules other
povlei~ could follow. In sum, the celebrations could not have
simply bounced around the calendar.
Precise placement of embolismic months, moreover, becomes
more complicated in actual practice than isolated mathematical
calculations can show. Today, for instance, one can retroactively
correct errors, run various scenarios using different criteria as
well as avoid any extenuating circumstances like disruptive sociopolitical events, inclement weather, or even unusually long, short,
mild, or severe seasonal climates. Ancient Athenian intercalations
must have had “rules,” which took all of the above into account.
Schemas
Math is everything. Herodotos’ tale of Solon gives 360 day
ordinary Civil Years possessing thirty-five intercalations
throughout each seventy year period (Hdt. 1.32.2-4). The
calculations of Meton, Euktemon et al. presuppose 354 days with
seven intercalations inside nineteen years (AYP pp. 51-55, 81-87,
198), and Kallippos determined twenty-eight intercalations inside
seventy-six years. Tucked inside Geminos’ account (8.26) are
three intercalated years inside every eight (ojktaeteriv~).
Censorinus, moreover, notes that Pythagoreans of Philolaos’
time proposed twenty-one intercalations inside fifty-nine years;
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
Demokritos twenty-eight inside eighty-two; and Hipparkhos 112
inside 304 (DN 7.18.8). All of these “schemas” reveal attempts to
predict future embolismic years. An observational calendar, on
the other hand, remains a different kind of creature. I withdraw
my observation of Censorinus (AYP 197):
Censorinus DN 7.18.2
Veteres in Graecia civitates cum animadverterent, dum sol
annua cursu orbem suum circumit, lunam novam interdum
tridecies exoriri idque saepe alternis fieri, arbitrate sunt
lunares duodecim menses et dimidiatum ad annum naturalem
convenire. Itaque annos civiles sic statuerunt, ut intercalando
facerent alternos duodecim mensum, alternos tredecim,
utrumque annum separatism vertentem, iunctos ambo annum
magnum vocantus; idque tempus trieterida appellabant, quod
tertio quoque anno intercalabatur, quamvis biennii circuitus et
re vera dieteris esset et cetaera.
His explanation (summation) only seems obtuse at first. After
further consideration, Censorinus preserves the remnants of just
such an observational lunisolar calendar. The critical part: an
intercalation would take place every third year (= trieteris) but in
two years (= dieteris). Rejecting his math denotes the difference
between inclusive and exclusive reckoning, the description
becomes truncated or incomplete (corrupt). I propose inserting
the words “at times” between the two counts.
Double Octaeteris: Allure & Failure
Patterns reside in the number of days from SumSol (as
reckoned) to the actual appearance of the initial 1stVisCres. By
AS a Boö, SumSol should have run (after Meton) 29, 28, 28, 28
Jun and thus the counts-of-days ran (by double octaeteris):
430/29 – 415/4
430
429
428
427
426
425
424
423
422
421
420
419
418
417
416
415
25
13
03
22
11
29
18
08
------BCE
27
BCE
15
BCE* 04
BCE* 23
BCE
12
BCE
01
BCE
20
BCE
09
BCE
BCE
BCE
BCE
BCE
BCE
BCE
BCE
Jul
O
Jul
O
Jul
I
Jul
O
Jul
O
Jun
I
Jul
O
Jul
I
------Jul
O
Jul
O
Jul
I
Jul
O
Jul
O
Jul
I
Jul
O
Jul
O
414/3 – 399/8
26
15
5
24
12
1
20
10
|
|
|
|
|
|
|
|
414
413
412
411
410
409
408
407
28
17
6
25
13
3
22
11
|
|
|
|
|
|
|
|
406
405
404
403
402
401
400
399
29
17
06
25
14
02
21
11
--------BCE
30
BCE
18
BCE
08
BCE
27
BCE
16
BCE
04
BCE
22
BCE
12
BCE
BCE
BCE
BCE
BCE
BCE
BCE
BCE
Jul
I
Jul
O
Jul
I
Jul
O
Jul
O
Jul
I
Jul
O
Jul
O
-------Jun
I
Jul
O
Jul
I
Jul
O
Jul
O
Jul
I
Jul
O
Jul
O
1
19
8
27
15
4
23
13
1
20
10
29
17
6
24
14
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
“*” = Chap XX, pp xxx-xxx. It goes without saying that the
dates represent how the years ought to have run (cf. AYP 178
Table 10, 185-187 viz. Table 16).
Buried in the above jumble of numbers reside sequences. The
first pattern, or perhaps the most noticeable one, begins with the
intercalation of 423 BCE. The 1stVisCres fell ten days after
SumSol. A repeating countdown then appears with each
subsequent intercalation: 10 6 3 1 - 8 4 1 - 10 6 4. The next
pattern reflects this one. The first ordinary years that follow then
run 28 25 22 19 - 27 23 20 - 29 24. Finally, the second ordinary
years after intercalation too possess a sequence, though they
become interrupted: 17 13 11 * - 15 13 * - 17 14.
The sequences simply stand incomplete. The double octaeteris
falls short to unlock how cyclical movements of the Moon repeat
against SumSol. The range needs extended. Meton, Euktemon et
al., for example, discovered the Moon against the Sun “resets” by
conjunction every nineteen years (e.g., 411 BCE ff. mirrors 430
BCE ff. mirroring 449 BCE ff). We shall go seventy.
By AS a Boö (before Meton), the number of days from SumSol
(as reckoned) to actual appearance of 1stVisCres ran from 30, 29,
29, 29 Jun. Consequently, numbers in parantheses denote the
counts as if SumSol had reckoned by 29, 28, 28, 28 Jun.
Expanding upon the previous table (again by double octaeteris):
462/1 – 447/6
462
461
460
459
458
457
456
455
454
453
452
451
450
449
448
447
19 Jul
07 Jul
26 Jul
16 Jul
05 Jul
23 Jul
12 Jul
01 Jul
-------BCE
20 Jul
BCE* 08 Jul
BCE* 27 Jul
BCE
17 Jul
BCE
07 Jul
BCE
25 Jul
BCE
14 Jul
BCE
03 Jul
BCE
BCE
BCE
BCE
BCE
BCE
BCE
BCE
398 BCE
397 BCE
396 BCE
02 Jul
20 Jul
09 Jul
446/5 – 431/0
O
19 (20)
446 BCE 22 Jul
I
8
(9)
445 BCE 10 Jul
O
27 (28)
444 BCE 29 Jun
O
17 (18)
443 BCE 18 Jul
I
5
(6)
442 BCE 08 Jul
O
24 (25)
441 BCE 26 Jul
O
13 (14)
440 BCE 16 Jul
I
2
(3)
439 BCE 05 Jul
--------------O
20 (21)
438 BCE 24 Jul
I
9
(10)
437 BCE 12 Jul
O
28 (29)
436 BCE 01 Jul
O
18 (19)
435 BCE 20 Jul
I
7
(8)
434 BCE* 09 Jul
O
26 (27)
433 BCE* 28 Jul
O
15 (16)
432 BCE 17 Jul
I
4
(4)
431 BCE 07 Jul
----------------------------------------------------I
3
395 BCE 29 Jun
O
22
394 BCE 17 Jul
O
11
393 BCE 05 Jul
O
22
O
11
I
0
O
19
I
8
O
27
O
17
I
6
-------O
24
O
13
I
2
O
21
I
9
O
28
O
18
I
9
I
O
I
(23)
(12)
(1)
(19)
(9)
(28)
(18)
(7)
(25)
(14)
(3)
(22)
(10)
(29)
(19)
1
19
7
“*” = years Meton’s revisions would have resulted in
intercalation changes, i.e., 453/2 & 434/3 BCE should run
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
ordinary with 452/1 & 433/2 BCE embolismic (both years = 28
Jun & 0). In any case, the patterns of days SumSol ↔ 1stVisCres
over the seventy years covered by the Primer ran (note: bracketed
numbers [#] = what should have happened):
a) intercalated:
b) 1st ordinary:
9 6 3 [0] – 8 4 1 – 9 7 3 [0] – 9 5 1 – 10 6 3 1 –
8 4 1 – 10 6 4 [1]
28 25 21 [19] – 27 23 19 – 28 25 22 [19] – 26 24
20 – 28 25 22 19 – 27 23 20 – 29 24 22 [19]
When the next set expands, however, the “interruptions” shift
throughout:
c) 2nd ordinary:
[*] 18 14 [10] – [*] 16 12 – [*] 18 14 [10] – [*] 15
12 – [*] 17 13 11 – [*] 15 13 – [*] 17 14 11
Interestingly, the ordinary years “sandwiched” between two
intercalated years can also complete the third sequence and thus
“fill the gaps:”
c) 2nd ordinary:
[20*] 18 14 [10] – [19*] 16 12 – [19*] 18 14 [10] –
[19*] 15 12 – [20*] 17 13 11 – [19*] 15 13 – [20*]
17 14 11
All three sequences run 4 3 4 3 4 3 4. Within the pattern,
embolismic years alternate between every third and second years
[3] 1 2 1 [3] 1 2 1 3 1 2 1 3 1. This final pattern in fact appears to
indicate what Censorinus meant when differentiating between the
trieteris and dieteris. At this point, the primary interval into which
ancient Greeks attempted to apply these patterns became the
ojktaethriv~, but buried inside this particular range was the
smaller pentaethriv~ or quadrennium.
Ancient Greeks discovered two oddities: 1) occasionally, three
intercalations did not occur during an ojktaethriv~; and 2) the
precise placement of embolismic years change (or rather rotate)
within quadrenniums over time (L → R).
462/1
454/3
446/5
438/7
430/29
422/1
414/3
406/5
398/7
→
→
→
→
→
→
→
→
→
455/4 BCE:
447/6 BCE:
439/8 BCE:
431/0 BCE:
423/2 BCE:
415/4 BCE:
407/6 BCE:
399/8 BCE:
[391/0] BCE:
OIOO
O[OI]O
OOIO
OOIO
OOIO
OOIO
IOIO
IOIO
IOOI
IOOI
IOOI
IOOI
OIOI
OIOI
OIOO
OIOO
OIOO
OI[OO]
Beginning with the Great Panathenaia year of 462/1 BCE, and
running through 387/6 BCE, as well as following a SumSol
reckoned throughout on 29, 28, 28, 28 Jun, each year’s
Hekatombaion noumhniva would have produced the following
sequences that read as a “countdown of days” (Read: L → R):
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
-- -- 4*]
[28 18 6*]
[27 16 5]
[28 18 7]
[26*15 5]
[28*17 6]
[27 15*4]
[29 17*6]
[28 15 4*]
[23 12 1]
[25 14 3]
[23*12 1]
[25*14 3]
[24 12*1]
[{25}13*3]
[23 13 1*]
[24 14 4*]
[23 13 1]
[20* 9]
[21*10 {0}]
[20 9*]
[22 10*{1}]
[20 10]
[22 11 1*]
[20 10]
[22 11 1]
k.t.l.
[19 8*]
[19 9]
[19 8]
[19*7]
“*” = Great Panathenaia year; {#} = what should have unfolded.
As expected, each set of numbers advance (or drift) toward
SumSol. The intervals unfold either in two sets of three years
then one set of two years or three sets of three years and one set
of two years. Both patterns repeat at consistent intervals but in
effect “reset” each time 1stVisCres fell less than ten but more
than four days after SumSol.
Additionally, eight years (ojktaethriv~) indeed comprise and
complete any two sets of three years and one set of two years (in
any combination). Moreover, sixteen years (duoeidhv~ ojktaethriv~)
will comprise and complete if the count begins with any set of two
years or with any three year set that falls just prior to a two year
set (in any combination).
The Problem: neither eight nor sixteen year counts of any
combination continue beyond three rotations. The sequence for
intercalations then shifts by one year.
Let us contrast these counts against Olympiad ojktaethrivdo~.
The overall pattern should remain the same, i.e., still possessing
the eight and sixteen year sequences. The question thus becomes
do the numbers change much if the starting year changes.
464/3
456/5
448/7
440/39
432/1
424/3
416/5
408/7
400/399
→
→
→
→
→
→
→
→
→
457/6
449/8
439/8
431/0
425/4
417/6
409/8
401/0
393/2
BCE:
BCE:
BCE:
BCE:
BCE:
BCE:
BCE:
BCE:
BCE:
OIOI
OIO[O]
OIOO
OIOO
OIOO
OIOO
OOIO
OOIO
OOIO
OOIO
[I]OIO
IOIO
IO[OI]
IOOI
IOOI
IOOI
IOOI
OIOI
Beginning Ol. 79.1, i.e., the ancient Attic Archontic Year when
those Olympian Games took place, and running from 464/3 BCE
through 393/2 BCE, as well as following a SumSol reckoned
throughout on 29, 28, 28, 28 Jun, each year’s Hekatombaion
noumhniva produces the following sequences that read as
“countdowns.” Note: the years overlap with the Great Panathenaia
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
beginning with the initial countdown. This starts with the 3rd
count of 20 days (again, read L → R):
[28*18 6]
[27 16*5]
[28 18*7]
[26 15 5*]
[28 17 6*]
[27 15 4]
[29 17 6]
--- 12*1]
[24 14*3]
[23 12 1*]
[25 14 3*]
[24 12 1]
[{25}13 3]
[23*13 1]
[24*14 4]
[20 9]
[21 10 {0}*]
[20 9]
[22 10 {1}]
[20*10]
[22*11 1]
[20 10*]
[22 11*1]
[19 8]
[19*9]
[19 8*]
[19 7]
ktl.
“*” = an Olympic Game year; {#} = what should have unfolded.
As expected, each set for Olympiad ojktaethrivdo~ that advance (or
drift) toward SumSol effectively follows the same pattern
witnessed for the Panathenaiad ojktaethrivdo~.
Once again, eight years (ojktaethriv~) indeed comprise and
complete any two sets of three years and one set of two years (in
any combination), while sixteen years (duoeidhv~ ojktaethriv~) will
comprise and complete if the count begins with any set of two
years or with any three year set that falls just prior to a two year
set (in any combination).
Both series present unavoidable consequences. A Great
Panathenaia had taken place during or immediately following an
intercalated year 1, 5, 9, 13, 17, 21, 25, 29, 37, 45, 53, 61, 69,
73, and 77, i.e., all except 33, 41, 49, 57, and 65. The Olympian
Games, moreover, would have taken place during or immediately
following an (Attic) intercalated year 5, 13, 21, 29, 33, 37, 41, 45,
and 49 (and also applied to 57).
Panhellenic panhvgurei, in sum, raise a myriad of complications
(and hurdles) for how ancient Athenians (and by extrapolation all
ancient Greek povlei~) determined intercalations, while also
accounting for (reckoning) events that affected multiple povlei~.
Excursus: Panhellenic Festivals
Ancient Greeks in fact gathered from all over the Hellenes to
celebrate four grand ajgw`ne~: two every four years (or rather on
every fifth year) and two every other year (or rather on every third
year). b More importantly, however, their individual schedules
resulted in at least one gathering taking place every single year
whether reckoned, for instance, by the ancient Athenian
Calendar(s) or by the ancient Roman Julian Calendar. In
addition, ancient Athenians held three annual “Panhellenic”
b) Other such festivals, in addition to the Great Panathenaia, took place, e.g., the Grand
Eleusinia (every fifth year) & the Delia (every sixth year).
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
gatherings: the Eleusinian Mysteries, the Mysteries of Agrai, and
the Dionysia Asty. In essence, ancient Greeks gathered for
Panhellenic celebrations at different locations every single year
and more than once throughout any given year.
The difficulties faced to schedule such gatherings successfully
for any society, where instantaneous communication did not (and
could not) exist, become rather apparent rather quickly. In short,
if the host povli~ capriciously invoked an embolismic year, which
abruptly “dislocates” a Panhellenic gathering a whole synodic
cycle, then the festival could not have remained readily
determined in a consistent (or expected) manner.
For example, the Mysteries of Eleusis always began on the
fifteenth day of the Attic Civil Month Boedromion. During
Ordinary Civil Years, this astronomically translates as “under a
waning Full Moon that appears around AutEqu.” The immediate
(and most basic) question: how would ancient Greeks from other
povlei~ know whether this meant the closest waning Full Moon
before or after VerEqu? Or, if the basileuv~ had “bumped” it?
The Great Panathenaia, on the other hand, always culminated
trivth fqivnonto~ Hek = first New Moon Conjunction that followed
the initial 1stVisCres after SumSol. All successful Panhellenic
panhvgurei must have followed a similar type of reckoning. This
particular portion of the discussion continues Chap. XX, pp. xxxxxx through Chap. XX, pp. xxx-xxx.
Accurate Alignments
One rather important conclusion reached in the Primer: for
ancient Greeks, Solstices & Equinoxes did not (existentially)
represent precise moments in time but rather finite periods of
time. Solstices, for instance, appear to align up to five consecutive
solar days that possess indiscernible differences, while Equinoxes
possess at least two such solar days (AYP 149-157).
If one takes into account further that an ancient Greek
hJliotrovpaion undoubtedly possessed not negligible margins-oferror, then ambiguities and uncertainties abound. Regardless, for
lunisolar calendars to function properly, every astronomical event
required a specific day or a finite set of days.
Through nothing more than running numbers by trial-anderror, which eventually resulted in a serious stack of discarded
spreadsheets, I eventually concluded that Meton, Euktemon, et
al. indeed successfully (and correctly) identified 28 Jun as
SumSol of 432 BCE. I still consider this a stunning achievement. c
c) Primarily because I refused to accept they could have measured Helios correctly.
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
A major assumption, however, must come into play. Meton,
Euktemon et al. duplicated (or had already accomplished) the
same fete for WinSol, and this effort has simply dropped from the
historical record. In any case, with both solstices in place,
determining each equinox then became matters of confirming
measurements and supportive math.
By 430 BCE (allowing for maturation and saturation of the
discovery), ancient Athenian astronomers ought have accepted,
and thus the basileuv~ (and ejkklhsiva) ought have reckoned AutEqu
on 28 Sept; WinSol on 25 Dec; VerEqu 26 Mar; and SumSol on
28 Jun (in seasonal order). This represents one of two separate
achievements by Meton et al. (Chap. XX, pp. xxx-xxx).
By 341 BCE, however, both AutEqu & WinSol had begun
drifting into 27 Sept & 24 Dec, while VerEqu & SumSol had (for
the most part) drifted primarily into 25 Mar & 27 Jun. The 4th
Century BCE, however, does not present an insurmountable
problem with how ancient Greek may have determined dates. As
late as 335/4 BCE, for instance, SumSol still occasionally fell on
28 Jun (03:52:42±), VerEqu on 26 Mar (01:37:38±), and AutEqu
on 28 Sept (02:34:37±), i.e., by modern delineations, which use
midnight to advance solar days. The questions now become how
rigorous subsequent measurements became and then the
margins-of-error they realized.
If a “typical” ancient Greek gnwvmwn from the pre-Hellenistic era
possessed measurement errors in the neighborhood of ±3 solar
days (AYP 149-157), then seasonal reckonings should have
become a matter of convention and tradition rather than, when
conducted, meticulously noting the differences produced by any
subsequent measurements (AYP 352 Spreadsheet XLII). The
operative response, in other words, would have become the
ancient Greek equivalent of “meh, close enough.”
On the other hand, when driven ancient astronomers after
Meton & Euktemon (e.g., Kallippos) conducted their own
observations and made calculations, discrepancies uncovered
would (in all likelihood) become corrections. More bluntly, later
astronomers concluded previous astronomers had erred. Helios
therefore never really moved away from the stars; the
(retroactively applied) math moved previous attempts closer to the
correct number, i.e., until ongoing measurements began drifting
outside all possible margins-of-error.
Additionally, once Meton et al. had established the “official”
dates for both solstices and both equinoxes, ancient Athenians
then deferred to the star Arktouros to regulate the four solar
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
events (AYP 157-159). While nowhere attested in ancient sources,
stipulated, the math appears unassailable (e.g., The Choiseul
Marble). These eight important dates then remained in place until
evidence Helios deviated from Arktouros accumulated. The
phenomenon practically forced Hipparkhos to unlock solstices
and equinoxes. As a result, by 127 BCE, he discovered Helios
indeed shifted against the stars (AYP 383n133). d
A related assumption, however, retroactively applies: Meton,
Euktemon, et al. had also corrected for what they concluded
represented (traditional) errors in reckoning. Ancient Greeks (or
at least ancient Athenians) had positioned solstices & equinoxes
at least one solar day too late. From the shift, their nineteen year
cycle emerged. This discussion will continue Chap. XX, pp. xxxxxx. Their efforts, moreover, “to correct” the astronomical
calendar emerged from “The Problem of 434/3 BCE.” This
discussion continues Chap. XX, pp. xxx-xxx.
Complications
When apparent alignments between Selene’s 1stVisCres and
Helios’ Solstices & Equinoxes occurred, precision ultimately
proves less consequential than presumed. This began as one of
the most difficult premises for me to accept. The finding, however,
does not apply so much to ancient Attike in isolation but rather
when considering ancient Attike against the rest of the ancient
Hellenes and vice versa.
Even though the present author holds ancient Greek
astronomers, and certainly ancient Athenian astronomers, grew
quite adept predicting on what solar day a 1stVisCres would
indeed appear, by no later than the immediately preceeding 3rdQ,
the possibility (and I would argue probability) exists that other
povlei~ not only used more formulaic calendars (e.g., ancient
Sparta [AYP 268-273]), e but that other povlei~ had also come to
use different phases of the Moon. Other ancient Greeks, for
instance, certainly used WinSol and equinoxes.
Additionally, simply because Meton, Euktemon, et al.
reckoned AutEqu 28 Sept; WinSol 25 Dec; VerEqu 26 Mar; and
SumSol 28 Jun, and (as argued) convinced ancient Athenians to
d) By ca. 170 BCE, manufacturing techniques and technology had apparently advanced
enough so that Hipparkhos came to suspect (at least) VerEqu did not follow sidereal
solar reckoning. He thus began duplicating the efforts of Meton, Euktemon, et al. His
recorded observations and calculations, moreover, reveal a mean dec(d) error of +7 min
(i.e., the sum of atmospheric refraction & parallax). Regardless, the Tropical Solar Year had
come into existence forever changing our understanding of the heavens.
e) See also Chap. XX, pp. xxx-xxx
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
adopt these dates, non sequitur the rest of ancient Greece
accepted them. “Ambiguities” (for lack of a better term) therefore
always existed. Ancient Greeks had nonetheless adapted and
(successfully) overcame these problems to create a plethora of
different yet regionally functional lunisolar calendars.
The Methodology
The solution is absurdly counterintuitive. To re-align the lunar
calendar with its parallel solar year requires two ambiguous
astronomical events to converge. This means specifically that the
precise solar days remained difficult to determine by observation.
Solstices & Equinoxes (mevn) had always proven ambiguous. For
the Moon (dev), every phase but the 1stVisCres & FinVisCres had
also proven at least somewhat ambiguous.
Specifically, Selene constantly changes shape in the sky. Thus
(mevn), she indeed produced phases, which appeared the same on
the same days across the entire Hellenes, but (dev) the shape
required judgement calls based on nothing more than simple lineof-sight. One ancient Greek opining the Moon had reached 25%
or 50% illumination became another ancient Greek’s opinion of
“not yet” or “too late” (AYP 145-149). I see no way to avoid
drawing this most rudimentary of inferences. f
To keep the present argument manageable, we shall assume
that all such judgement calls possessed margins-of-error of (at
most) ±2 Solar Day between different povlei~, i.e., a ¼, 1stQ, Full,
3rdQ, ¾, and New Moon always reckoned within two solar days
of each other throughout the Hellenes regardless of the regional
judgments made or the lunisolar methodology followed.
The FinVisCres, on the other hand, always vanished on a
specific day; the following 1stVisCres then always appeared on a
specific solar day. Both days remained exact whether or not
predicted accurately or accurately rendered by some formula. The
key “ambiguous” astronomical event thus rested between the two.
The New Moon provides a “window” of roughly three Solar Days.
The 1stVisCres undoubtedly marked noumhniva for every Attic
Civil Month, but, following the presented line-of-reasoning,
Ancient Athenians in fact based their ancient Attic Archontic
(Civil) Calendar on both solstices and both equinoxes against four
f) No student of ancient Athenian Calendars should use me as a barometer, but the more I
have watched the Moon, the more I understand too many variables exist to conclude
definitively how ancient Greeks from different povlei~ determined lunar reckonings.
Observations made, for example, around Nautical to Astronomical Twilight at dusk can
differ from those made around Astronomical to Nautical Twilight at dawn. I remain
convinced, however, that each povli~ possessed an “official” platform.
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
of twelve regularly repeating New Moons, i.e., ancient Attic Impure
Days (see previous Chap.). Specifically, during all Ordinary Civil
Years, the counts of days between these sixteen baseline
astronomical events ran consistently against each other without
producing convergences.
When two of these “ambiguous” astronomical events, i.e., one
solar and one lunar, did converge, however, ancient Athenian
astronomers then artificially reckoned one or the other (but not
both) as unambiguous. In other words, they assigned one of them
to a specific day. In theory, ancient Athenian astronomers could
have kept the solstices and equinoxes ambiguous against a
precise Conjunction, or they could have used the ambiguous New
Moon against precisely reckoned solstices and equinoxs.
Both methodologies will typically but not always produce the
same results to determine seasonally accurate intercalations as
long as each followed essentially the same underlying premise.
For example, if ancient Greeks considered solstices and
equinoxes lasted, say, three solar days, then the “benchmark”
1stVisCres must appear after the final day of the solstice or
equinox in question. Conversely, if a New Moon lasts three days,
then the solstice or equinox in question must fall during them.
Both rules would effectively force the “calibration” 1stVisCres
beyond the solstice or equinox.
Once again, math becomes everything. Ancient Attic Archontic
Months (and by extrapolation all ancient Greek Lunar [Civil]
Months] represented specific Synodic Cycles that ought arrive
before, run through, or begin after a particular solstice or
equinox. For example, if Synodic Cycle I began before but ended
after SumSol, then Synodic Cycle IV would begin before but end
after AutEqu. Synodic Cycle VII would then begin before and end
after WinSol, and Synodic Cycle X before and after VerEqu.
Consequently, in ancient Attike, during Ordinary Civil Years,
Hek (ought) always equate to the first complete Synodic Cycle
that began and ended after SumSol (or Synodic Cycle II); Pyan
(ought) always equate to the first complete Synodic Cycle, which
began and ended after AutEqu (or Synodic Cycle V); Gam (ought)
always equate to the first complete Synodic Cycle that began and
ended after WinSol (or Synodic Cycle VIII); and Moun (ought)
always equate to the complete Synodic Cycle, which began and
ended after VerEqu (or Synodic Cycle XI).
As Lunar Years advanced against the Sidereal Solar Year, thus
drifted outside these seasonal alignments, the inevitable shift
that approached demanded an adjustment. Scholars (including
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
this one), however, have erred on the purposes embolismic
months served. An intercalation in fact possessed two different
applications: one in practice and then a second in purpose.
Everyone focuses on the former.
As mentioned above (p. xxx), the Primer did not address
whether the four key seasonal events should fall within the
nominal ordinary month (AutEqu = Cycle III [Boid]; WinSol =
Cycle VI [Pos]; VerEqu = Cycle IX [Elaph]; and SumSol = Cycle XII
[Skir]) or could just as readily fall during its embolismic month.
The decision here dictates placement of the intercalation.
If ancient Athenians did not consider a Civil Year seasonally
aligned when key solar events fell within Month III2, VI2, IX2, or
XII2, then the intercalated month must insert before Month III, VI,
IX, or XII. This restriction, however, creates the alignment
problems explored. The second option, on the other hand, makes
the first one an unnecessary conundrum. The two posited
“meanings” of an intercalation rather complement each other.
An embolismic month existentially represented an additional,
or, more specifically, a thirteenth, synodic cycle between two
occurrences of the same solar event (e.g., SumSol ↔ SumSol or
VerEqu ↔ VerEqu). This becomes the practical application.
Conceptually, however, each intercalation produced an
“elongated” Civil Month. This was the purpose. The month in
question became comprised of two consecutive synodic cycles. It
now possessed a) two sets of ten waxing days; b) two sets of ten
middle days; and finally c) two sets of (up to) ten waning days.
The Civil Month, in effect becomes one running 58 ↔ 60 days
All “problematic alignments” now promptly vanish. The
findings not only challenge my proposed Civil Calendar Rules e
(Chap. X, p. xx) but also one of the most fundamental
assumptions accepted today: 1 Hek could fall on SumSol. Outside
observational or calculation errors, which undoubtedly occurred
time-to-time, such an alignment ultimately proves untenable to
maintain an effectively functional lunisolar calendar precisely
because of the problematic math it produces. g
A 1stVisCres therefore determined when an ancient Athenian
Civil Month began, not to mention the next Archontic Year, but
its appearance did not determine the proper placements of
intercalations. This duty deferred to the immediately preceeding
g) I have set aside Prof. Pritchett’s more extreme skepticism. By extrapolation, the
observation also means 1 Boid should not fall on AutEqu, 1 Pos on WinSol, and 1 Elaph
on VerEqu. Even though some of these alignments would prove mathematically
impossible depending when 1 Hek fell after SumSol, the principle stands.
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
New Moon. Ancient Athenians, in other words, used this small
but adequate “window” into which the four ambiguous solstices
and equinoxes would at times fall to their advantage.
For example, the exact days the four key solar events fell (mevn)
may or may not have proven correct. I proposed, for instance,
that all measurements inherently possessed a margin-of-error of
approx. three solar days. Similarly (dev), at least some povlei~ in all
probability reckoned solstices and equinoxes on different days.
Sans utter indifference or incompetence, these too should not
have differed more than (at most) three solar days.
Assuming both inferences sound, then, by using an ambiguous
astronomical event, either a solstice or equinox lasting three days
or a Moon phase of three days, the differences ultimately become
immaterial or at least substantially less relevant to calculate and
place an Embolismic Civil Month. h
Adjusted Math
This new hypothesis for New Moons and Embolismic Civil
Years affects the math for years 445/4 ↔ 444/3; 434/3 ↔
433/2; 423/2 ↔ 422/1; and 415/4 ↔ 414/3 BCE as well as
(possibly) the years 453/2 ↔ 452/1; 426/5 ↔ 425/4; 407/6 ↔
406/5; and 396/5 ↔ 395/4 BCE.
Note: Julian Date = 1 Hek; First “#” = days after SumSol when
reckoned 30, 29, 29, 29 Jun; Second “(#)” = days after SumSol
when reckoned 29, 28, 28, 28 Jun; Years listed by ojktaethriv~.
462/1 – 447/6
462
461
460
459
458
457
456
455
BCE
BCE
BCE
BCE
BCE
BCE
BCE
BCE
454
453
452
451
450
449
448
447
BCE
BCE
BCE
BCE
BCE
BCE
BCE
BCE
19 Jul
07 Jul
26 Jul
16 Jul
05 Jul
23 Jul
12 Jul
01 Jul
-------20 Jul
08 Jul
27 Jul
17 Jul
07 Jul
25 Jul
14 Jul
03 Jul
O
19
I
08
O
27
O
17
I
05
O
24
O
13
I
02
-------O
20
I
09
O
28
O
18
I
07
O
26
O
15
I
04
446/5 – 431/0
(20)
(09)
(28)
(18)
(06)
(25)
(14)
(03)
|
|
|
|
|
|
|
|
446
445
444
443
442
441
440
439
BCE
BCE
BCE
BCE
BCE
BCE
BCE
BCE
(21)
(10)
(29)
(19)
(08)
(27)
(16)
(04)
|
|
|
|
|
|
|
|
438
437
436
435
434
433
432
431
BCE
BCE
BCE
BCE
BCE
BCE
BCE
BCE
22 Jul
10 Jul
29 Jul
18 Jul
08 Jul
26 Jul
16 Jul
05 Jul
-------24 Jul
12 Jul
01 Jul
20 Jul
09 Jul
27 Jul
17 Jul
07 Jul
O
22
I
11
O
30
O
19
I
08
O
27
O
17
I
06
-------O
24
O
13
I
02
O
21
I
09
O
28
O
18
I
08
(23)
(12)
(31)
(19)
(09)
(28)
(18)
(07)
(25)
(14)
(03)
(22)
(10)
(29)
(19)
(09)
h) Unless, of course, reckonings indeed differed more than three solar days. Such a spread,
however, seems unlikely. The Olympian Games, for instance, had used SumSol since the
8th Century BCE. Three centuries becomes time enough to agree. Chap. XX, pp. xxx-xxx.
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
Note: At this point, each ojktaethriv~ follows from Meton’s et al.
adjustments (Chap. XX, pp. xxx-xxx). Julian Date = 1 Hek; First
“#” = days after SumSol when reckoned 29, 28, 28, 28 Jun. See
Chap. XX, pp. xxx-xxx for the years 420/19* & 419/8* BCE. I
shall go ahead and finish the ninth ojktaethriv~
430/29 – 415/4
430
429
428
427
426
425
424
423
422
421
420
419
418
417
416
415
414/3 – 399/8
25 Jul
O
26 |
414 BCE 28 Jul
O
13 Jul
O
15 |
413 BCE 17 Jul
O
03 Jul
I
05 |
412 BCE 06 Jul
I
22 Jul
O
24 |
411 BCE 25 Jul
O
11 Jul
O
12 |
410 BCE 14 Jul
O
29 Jun
I
01 |
409 BCE 02 Jul
I
18 Jul
O
20 |
408 BCE 21 Jul
O
08 Jul
I
10 |
407 BCE 11 Jul
O
---------------------------BCE
27 Jul
O
28 |
406 BCE 30 Jun
I
BCE
15 Jul
O
17 |
405 BCE 18 Jul
O
BCE* 04 Jul
I
06 |
404 BCE 08 Jul
I
BCE* 23 Jul
O
25 |
403 BCE 27 Jul
O
BCE
12 Jul
O
13 |
402 BCE 16 Jul
O
BCE
01 Jul
I
03 |
401 BCE 04 Jul
I
BCE
20 Jul
O
22 |
400 BCE 22 Jul
O
BCE
09 Jul
I
11 |
399 BCE 12 Jul
O
-----------------------------------------------------------------I
03
398 BCE 02 Jul
397 BCE 20 Jul
O
22
396 BCE 09 Jul
O
11
395 BCE 29 Jun
I
01
394 BCE 17 Jul
O
18
393 BCE 05 Jul
I
07
392 BCE 25 Jul
O
27
391 BCE 14 Jul
O
16
BCE
BCE
BCE
BCE
BCE
BCE
BCE
BCE
30
19
08
27
15
04
23
13
01
20
10
29
17
06
24
14
The adjusted counts of days (i.e., the post-Meton shift) for a
SumSol ↔ 1stVisCres sequence that instead follow the New Moon
hypothesis for the seventy-two years run:
a) intercalated:
b) 1st ordinary:
c) 2nd ordinary:
9 6 3 – 10 8 4 – 12 9 7 3 – 10 9 5 1 – 10 6 3 –
11 8 4 1 – 10 6 3 1 - 7
28 25 21 – 29 27 23 – 31 28 25 22 – 29 26 24
20 – 28 25 22 – 30 27 23 20 – 29 24 22 18 - 27
18 14 – 19 16 – 19 18 14 – 19 15 12 – 17 13 19 15 13 – 17 14 11 - 16
Once again, expanding the second ordinary year after
intercalation to include those quadrenniums, which did not
possess one, those sequences run:
d) 2nd ordinary:
18 14 – [21] 19 16 – [23] 19 18 14 – [22] 19 15
12 – [20] 17 13 - [22] 19 15 13 – [20] 17 14 11 –
[18] 16
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
All three sequences do not in fact alternate 4 3 4 3 4 3 4 but
rather 4 4 3 4 4 3 4 4. Within this pattern, embolismic years do
not alternate between every third and second years [3] 1 2 1 [3] 1
2 1 3 1 2 1 3 1 but rather 2 1 2 1 3 1 2 1 2 1 3 1. In sum, the
earlier sequences represent “true” Synodic Cycle counts, while
these new sequences represent Civil Month designations.
Such determinations, however, followed from constant and
continuous astronomical observations. Predicting what would
happen during the current synodic cycle or during the current
seasonal year proves an entirely different undertaking than
predicting what might happen several years in advance. Put
another way, understanding next year would run embolismic
became considerably less daunting than predicting how many
embolismic years would exist during the next sixteen. Most
ancient Greeks (dev) undoubtedly lived by the former; ancient
Greek astronomers (mevn) sought to unlock the latter.
Sitting silently behind the present analysis, moreover, rest the
(so far) briefly mentioned Panhellenic celebrations. Had ancient
Greeks not held such gatherings, accurate lunisolar calendars
would have remained far less consequential for any povli~ in
question. Ancient Athenians, as stressed, hosted four such
gatherings. These of course remained subject to the ancient Attic
Archontic Calendar but also impacted other povlei~.
The logic also flows in reverse. How much consideration would
ancient Athenians have given to the Olympian, Pythian, Isthmian,
and Nemeian Games? Did it matter during which ancient Attic
Archontic Month these took place? Once again, this particular
discussion continues Chpts. XX-XX, pp. xxx-xxx.
Conclusions
Four criteria became recognized and eventually manipulated
so ancient Athenians could invoke embolismic years effectively.
The methodology that positioned all ancient Attic Archontic
intercalations emerged from:
1) The SumSol’s exact alignment remained ambiguous but still
required a specific day assigned;
2) The three other key solar events (AutEqu, WinSol, VerEqu),
though ambiguous as well, nevertheless also required
specific days assigned;
3) The occasional alignments between these solar events and
New Moons dictated the count of Synodic Cycles;
4) All Panhellenic Celebrations demanded consistent schedules
to prove not only successful but simply functional.
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
We shall set aside #4 until Chpts. XX-XX, pp. xxx-xxx. For
now, however, the basic principles that guide intercalations also
apply to Panhellenic celebrations: to gather again from all over
the Hellenes, each panhvguri~ must have aligned to a specific
Synodic Cycle in relation to a solar “anchor,” i.e., an event like a
solstice, equinox, or the rising/setting of a star. The two
questions, which remain, become a) “how” and then b) does
“specific Synodic Cycle” = “particular Civil Month.”
In any case, the first three criteria almost assuredly evolved
over a not insignificant period of time. Attempts to make sense of
the sky, moreover, and then use it to establish order for ancient
Greek daily lives, had become (partly) established (at least) as far
back as Hesiodos and Homeros. In ancient Attike, the calendrical
reforms introduced by Solon suggest capabilities had advanced
far enough to follow the methodology proposed here. Meton,
Euktemon, et al. then refined ancient Athenian astronomers’
understanding of the sky further by uncovering the nineteen year
“reset.” At that point, ancient Greek astronomers (figuratively
speaking) went “off to the races.”
Looking at the whole intercalation methodology from the other
side of the equation, inserting an embolismic month seasonally
too early or too late or advancing or retarding lunisolar years by
omitting an anticipated intercalation or inserting unnecessarily
an additional embolismic month all came with considerable costs.
Each scenario displaces or disrupts seasonal alignments for all
subsequent Civil Months that follow. The Anthesteria, for
instance, ought take place when ancient Athenians opened the
season’s wine vats (AYP 237 n. y; Chap. XX, pp. xxx-xxx).
In addition, “wayward intercalations” could “bump” any of the
four ancient Attic Panhellenic gatherings (Great Panathenaia,
Eleusinian Mysteries, Mysteries of Agrai, and the City Dionysia).
Three of these festivals, moreover, also represented decidedly
seasonal events. Unexpected or skipped intercalations could also
shift any of the expected ancient Attic monthly alignments for the
Olympian, Pythian, Nemeian, and Isthmian Games. Each of these
complications represent formidable hurdles that, quite bluntly, a
basileuv~ or ejkklhsiva could not flippantly ignore.
I do not, however, arrogantly presume ancient Athenians never
omitted a scheduled intercalation nor ever inserted an additional
embolismic month. I seek rather only to stress that such actions
should ultimately prove extremely rare. The latter certainly took
place 190/89 → 189/8 BCE (IG II/III3 1, 1268-1271, 1273-1274;
AYP 223-237), and the former (probably) took place 420/19 →
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
419/8 BCE (Antiph. 6.44-45; AYP 185-186). i When uncovered
epigraphic evidence therefore reveals such disruptive deviations
actually occured, the question promptly becomes (or ought to
become) “why.”
One hypothesis, for instance, which I have proposed as a
possibility: exceptional seasonal weather like an unusually long
and harsh Winter. Such an event would have affected most if not
all of the Hellenes and could have thus “forced” an extra
intercalation to keep the Spring sailing season as well as the (now
delayed) Summer harvests aligned within the ancient Archontic
Calendar (for a possible example in Thoukydides, see Chap. XX,
pp. xxx-xxx).
Finally, at the risk of repeating a point ad nauseam, different
magistrates down through the centuries probably held different
opinions on what represented the optimal (or most prudent)
courses of action to take. Other magistrates, moreover, may have
faced unheard circumstances. Regardless, they each at times
certainly faced different situations.
Additionally, societies evolve. Prerequisites change. Any driving
considerations in play thus move. What may have worked during
the 5th & 4th Centuries BCE, for example, may not have been
prudent by the 2nd Century BCE. j
Example: if the author’s hypotheses regarding the significance
of the Apatouria to establish a) every ancient Athenian’s politeiva
and then b) every ancient Athenian’s (legal) age to claim that
politeiva proves sound (Chpts. XX-XX, pp. xxx-xxx), then the
festival’s seasonal alignment to late-Fall ↔ early-Win (Pryt. III ↔
IV) possessed considerable cultural significance. At some point
during the 3rd Century, however, practically all mentions of this
festival drop from the historical record. This could reveal a simple
accident of history, or it shows that the Apatouria had in fact lost
its significance. Consequently, the necessary seasonal alignment
dimishes perhaps even vanishes. 14
The common denominator nonetheless always remained: the
ancient Athenian Calendars required following the Moon to the
best of their abilities.
i) See also Chap. XX, pp. xxx-xxx
j) Although cumbersome to illustrate with specific examples, the never-ending and
unresolved feud(s) between Profs. Meritt & Pritchett reveal they both (at times)
overlooked this very real possibility. Just because some action taken during Century X
exists does not ipso facto mean it ought also apply to Century Y. In essence, watching and
following the sky always took place; the variable(s) became the decisions that followed at
the time(s) a judgment call became required.
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
Table X: 462/1 to 433/1 BCE
Julian
Year
Civil
Intercalation
Hek. 1
Number
of Days
462/1
461/0
460/59
459/8
458/7
457/6
456/5
455/4
454/3
453/2
O
IS
O
O
V I S
O
O
S I A
O
V I S
19 July
07 July
26 July
16 July
05 July
23 July
12 July
01 July
20 July
08 July
354
384
355
354
384
354
354
384
354
384
O
O
IS
O
O
V I S
O
V I S
O
O
27 July
17 July
07 July
25 July
14 July
03 July
22 July
10 July
29 July
18 July
VI S
08 July
26 July
16 July
05 July
24 July
12 July
1 July
20 July
09 July
27 July
452/1
451/0
450/49
449/8
448/7
447/6
446/5
445/4
444/3
443/2
442/1
441/0
440/39
439/8
438/7
437/6
436/5
435/4
434/3
433/2
V
V
O
O
VI S
O
O
S I A
O
V I S
O
Calendar
Equation
Pryt.
I.1
Number
of Days
Conciliar
Intercalation
Calendar
Equation
Full /
Hollow
= Pryt I.16
= Pryt I.05
= Pryt I.24
= Pryt I.14
= Pryt I.02
= Pryt I.21
= Pryt I.10
= Pryt X.34
= Pryt I.17
= Pryt I.06
4 July
3 July
3 July
3 July
4 July
3 July
3 July
3 July
4 July
3 July
365
365
365
366
365
365
365
366
365
365
O
O
O
I
O
O
O
I
O
O
= Skir 16
= Skir 27
= II Skir 7
= Skir 18
= Skir 29
= Skir 10
= Skir 21
= Hek 03
= Skir 14
= Skir 25
F (+)
H (-)
H (-)
F (+)
H (-)
H (-)
H (-)
[H (-)]
H (-)
H (-)
355
355
384
354
354
384
354
384
354
355
= Pryt I.25
= Pryt I.15
= Pryt I.04
= Pryt I.23
= Pryt I.12
= Pryt I.01
= Pryt I.19
= Pryt I.08
= Pryt I.27
= Pryt I.16
3 July
3 July
4 July
3 July
3 July
3 July
4 July
3 July
3 July
3 July
365
366
365
365
365
366
365
365
365
366
O
I
O
O
O
I
O
O
O
I
= II Skir 6
= Skir 16
= Skir 28
= II Skir 9
= Skir 19
= Hek 01
= Skir 13
= Skir 24
= II Skir 5
= Skir 15
H (-)
H (-)
F (+)
F (+)
H (-)
[H (-)]
F (+)
F (+)
F (+)
H (-)
384
355
354
384
354
354
384
354
384
355
= Pryt I.05
= Pryt I.24
= Pryt I.14
= Pryt I.03
= Pryt I.21
= Pryt I.10
= Pryt X.34
= Pryt I.18
= Pryt I.06
= Pryt I.25
4 July
3 July
3 July
3 July
4 July
3 July
3 July
3 July
4 July
3 July
365
365
365
366
365
365
365
366
365
365
O
O
O
I
O
O
O
I
O
O
= Skir 26
= II Skir 7
= Skir 18
= Skir 29
= Skir 11
= Skir 22
= Hek 03
= Skir 14
= Skir 25
= II Skir 6
H (-)
H (-)
F (+)
F (+)
F (+)
F (+)
[F (+)]
F (+)
H (-)
H (-)
Civil Intercalation:
V
I S
IA
A I W
W I V
S
After VerEqu
After SumSol
After AutEqu
After WinSol
Before SumSol
Before AutEqu
Before WinSol
Before VerEqu
Theory:
Theory:
Theory:
Theory:
2nd
2nd
2nd
2nd
Elaph, Moun, Thar, or Skir
Hek, Met, or Boid
Boid, Pyan, Maim, or Pos
Pos, Gam, Anth, or Elaph
Actual:
Actual:
Actual:
Actual:
Thar, Skir
Boid
Pos
Elaph
Tables here supercede Tables 9-10 & 15 in AYP (pp. 177-178, 180). I
now consider those obsolete. k For the years 426/5-423/2 BCE, moreover,
see Chap. XX, pp. xxx-xxx = The Logistai Inscription. The years 420/19
& 419/8 BCE are addressed Chap. XX (pp. xxx-xxx) = Antiphon VI. The
analysis of IG I3 377 (= IG I2 304B = Tod 92 = Fornara 158) presented in
the Primer (pp. 207-214) stands = The Choiseul Marble.
Additionally, this seventy year schema shows what ought have
unfolded if ancient Athenians had continuously, rigidly, and accurately
followed astronomical reckonings for both the Archontic and Boulitic
Calendars. In other words, these Calendar Equations present the oft
needed but ever elusive baseline or calibration “template.”
k) More specifically, the Tables given in the Primer (mevn) offer an attempted summation (or
synthesis) of ancient Athenian calendrical studies as they then existed. The present
Tables (dev) reflect my contribution to those debates. I have no doubt both Profs. Meritt &
Pritchett would have vigorously objected to (parts of) my proposals.
CHRISTOPHER PLANEAUX
ATTIC INTERCALATIONS
Table X: 432/1 to 403/2 BCE
Julian
Year
Civil
Intercalation
Hek. 1
Number
of Days
432/1
431/0
430/29
429/8
428/7
427/6
426/5
425/4
424/3
423/2
O
IS
O
O
WI V
O
O
S I A
O
V I S
17 July
07 July
25 July
13 July
03 July
22 July
11 July
29 June
18 July
08 July
355
383
354
355
384
354
354
384
355
384
O
O
27 July
15 July
04 July
23 July
12 July
01 July
20 July
09 July
28 July
17 July
06 July
25 July
14 July
02 July
21 July
11 July
30 June
18 July
08 July
27 July
422/1
421/0
420/19
419/8
418/7
417/6
416/5
415/4
414/3
413/2
412/1
411/0
410/09
409/8
408/7
407/6
406/5
405/4
404/3
403/2
V
WI V
O
O
S I A
O
V I S
O
O
V
IS
O
O
W I V
O
O
S I A
O
V I S
O
(Option 1)
Calendar
Equation
Pryt.
I.1
Number
of Days
Conciliar
Intercalation
Calendar
Equation
Full /
Hollow
= Pryt I.15
= Pryt I.05
= Pryt I.22
= Pryt I.11
= Pryt I.01
= Pryt I.20
= Pryt I.08
= Pryt X.32
= Pryt I.16
= Pryt I.06
3 July
3 July
4 July
3 July
3 July
3 July
4 July
3 July
3 July
3 July
365
366
365
365
365
366
365
365
365
371
O
I
O
O
O
I
O
O
O
[I]
= Skir 16
= Skir 27
= II Skir 9
= Skir 20
= Hek 01
= Skir 12
= Skir 24
= Hek 05
= Skir 15
= Skir 25
H (-)
F (+)
H (-)
H (-)
[F (+)]
F (+)
F (+)
[H (-)]
H (-)
H (-)
354
354
384
354
355
384
354
384
355
354
= Pryt I.19
= Pryt I.08
= Pryt X.32
= Pryt I.15
= Pryt I.04
= Pryt X.29
= Pryt I.12
= Pryt I.01
= Pryt I.20
= Pryt I.10
9 July
8 July
9 July
9 July
9 July
8 July
9 July
9 July
9 July
8 July
365
366
365
365
365
366
365
365
365
366
O
I
O
O
O
I
O
O
O
I
= II Skir 13
= Skir 23
= Hek 06
= Skir 17
= Skir 27
= Hek 08
= Skir 20
= Hek 01
= II Skir 11
= Skir 22
F (+)
H (-)
[H (-)]
F (+)
H (-)
[F (+)]
F (+)
[H (-)]
H (-)
F (+)
384
354
354
384
355
354
384
355
384
354
= Pryt X.34
= Pryt I.17
= Pryt I.06
= Pryt X.30
= Pryt I.13
= Pryt I.01
= Pryt I.01
= Pryt I.01
= Pryt I.01
= Pryt I.01
9 July
9 July
9 July
8 July
9 July
11 Jul
30 Jun
18 Jul
08 Jul
27 Jul
365
365
365
366
367
354
384
355
384
354
O
O
O
I
[I]
O
I
O
I
O
= Hek 04
= II Skir 15
= Skir 26
= Hek 07
= Skir 18
= Hek 01
= Hek 01
= Hek 01
= Hek 01
= Hek 01
[F (+)]
F (+)
F (+)
[H (-)]
H (-)
[F (+)]
[H (-)]
[H (-)]
[F (+)]
[F (+)]
Calendar
Equation
Pryt. I.1
Number
of Days
Conciliar
Intercal.
Calendar
Equation
Full /
Hollow
= Pryt I.01
= Pryt I.01
= Pryt I.01
= Pryt I.01
= Pryt I.01
= Pryt I.01
= Pryt I.01
= Pryt I.01
= Pryt I.01
= Pryt I.01
16 July
4 July
22 July
12 July
2 July
20 July
9 July
29 June
17 July
5 July
354
383
355
355
384
354
355
383
354
384
O
I
O
O
I
O
O
I
O
I
Table X: 402/1 to 393/2 BCE
Julian
Year
Civil
Intercal.
Hek. 1
Number
of Days
402/1
401/0
400/399
399/8
398/7
397/6
396/5
395/4
394/3
393/2
O
IS
O
O
S I A
O
O
S I A
O
V I S
16 July
04 July
22 July
12 July
02 July
20 July
09 July
29 June
17 July
05 July
354
383
355
355
384
354
355
383
354
384
V
= Hek 01
= Hek 01
= Hek 01
= Hek 01
= Hek 01
= Hek 01
= Hek 01
= Hek 01
= Hek 01
= Hek 01
[F (+)]
[H (+)]
[H (-)]
[F (+)]
[F (+)]
[F (+)]
[H (-)]
[F (+)]
[H (-)]
[H (-)]
Civil Intercalation:
V
I S
IA
A I W
W I V
S
After VerEqu
After SumSol
After AutEqu
After WinSol
Before SumSol
Before AutEqu
Before WinSol
Before VerEqu
Theory:
Theory:
Theory:
Theory:
2nd
2nd
2nd
2nd
Elaph, Moun, Thar, or Skir
Hek, Met, or Boid
Boid, Pyan, Maim, or Pos
Pos, Gam, Anth, or Elaph
Actual:
Actual:
Actual:
Actual:
Thar, Skir
Boid
Pos
Elaph
CHRISTOPHER PLANEAUX
ENDNOTES
inside 384 Days: 461/0, 458/7, 455/4, 453/2, 444/3, 442/1, [434/3], 425/4, [423/2], [419/8],
409/8, 406/5, and 393/2 BCE; finally, 354 inside 383 Days: 395/4 BCE.
10
Pleiavde~: the ancient identification for what marked a “rising” and “setting” of this
asterism within the constellation Taurus, or simply a constellation itself, becomes a bit
more complicated than perhaps appreciated. Nine stars, which by naked eye indeed
appear as seven, span more than a degree (or four minutes) across the sky: Atlas (27
Tau), Pleione (28 Tau), Alkyone (h Tau), Merope (23 Tau), Maia (20 Tau), Elektra (17
Tau), Celaeno (16 Tau), Asterope (21 Tau), and Taygeta (q Tau). Galilea Galilei, for
instance, identified thirty-six stars within the cluster, e.g. Asterope is actually two stars
(Sterope I & II); Alkyone = brightest (mag. 2.85).
Consequently, what the “typical ancient Greek farmer” living during the Classical Age
(if such a creature ever existed) would have considered as the “Pleiades”appearing and
disappearing upon the horizon grows frustratingly obtuse, i.e., whether just some or
most or all or only the brightest star(s) must first appear or disappear when the Sun rises
or sets to mark the specific day. AYP 245-248, 279.
11
Third reason: HR h Tau (Alkyone) thus the Pleiades occurred in Attike approx. 4:47 on
29/30 Apr @ LHA 17h20m or Az. +73°04′ (ca. 461 bce). This puts the cluster just north of
due east from Lykabettos Hill. More importantly, Helios resided about 5° to the north
just entering Civil Twilight at the time. Spotting Alkyone, unlike Arktouros, would take
some effort and skill thus the first appreance not proving obvious or clear.
12
The rest of the chapter synthesizes material from D. MacDowell, Athenian Homicide Law
in the Age of the Orators (Manchester 1963); The Law of Classical Athens, Aspects of Greek
and Roman Life, ed. H. Scullard (Ithaca 1978) 113-122; M. Gagarin, Drakon and Early
Athenian Homicide Law (New Haven 1981); R. Parker, Miasma: Pollution and Purification in
Early Greek Religion (Oxford 1983); A. Boegehold, The Lawcourts at Athens: Sites, Buildings,
Equipment, Procedure and Testimonia, Athenian Agora XXVIII (Princeton 1995); A
Harrison, The Law of Athens: Volume II2 (London 1998) 36-43; I. Arnaoutoglou, Ancient
Greek Laws: A Sourcebook (New York 1998) 71-73.
13
This statement possesses caveats for risings and settings. The precise angle of lunar orbit
to the visible horizon changes with the latitude of the observer. Latitude also affects the
times that the Moon becomes visible over the horizon as well as when it vanishes along
the same Longitude. Elevation of the observer will also affect the precise time the Moon
becomes visible or disappears. AYP 97-130.
14
Phratries (fratrivai) in general and the Apatouria in particular, with regard to ancient
Athenian politeiva, remains a rather involved and quite complex debate. The inference
here nonetheless becomes the ritual festival’s signifigance diminished. Parker, ARH 270;
S. Lambert, The Phratries of Attica, Michigan Monographs in Classical Antiquity (Ann
Arbor 1993) 143-189.
15
D. Feeney, Caesar’s Calendar: Ancient Time and the Beginnings of History (Berkeley 2007); J.
Rüpke, The Roman Calendar from Numa to Constantine: Time, History and the Fasti (Wiley
2011).
16
See RE s.v. “Kalendar;” E. Bickerman, Chronology of the Ancient World, Aspects of Greek
and Roman Life, H. Scullard, ed. (Ithaca 1974) 20-21 with bibliography.
Christopher Planeaux